I wrote the following research paper for an Advanced Acoustics class at New York University in the Spring of 2001 while obtaining my masters degree in Music Technology. I graduated in 2001.
Listening Examples to accompany the research paper are below:
Music Examples:
 
Love Song - by Elaine Walker, 2007
Stick Men - by Elaine Walker, 1992
1-rx^2 - by Elaine Walker, 1992

Composed in MAX using Chaos Melody Theory TM

Movement 1 | Movement 2 | Movement 3 | Movement 4
I Know of No Geometry - by Dr. Richard Boulanger
Solemn Song for Evening - By Dr. Richard Boulanger
For Radio Baton & Voice: Maureen Chowning - Soprano

Movement 2 | Movement 3
Heinz Bohlen’s homemade BP Scale keyboard (above). Heinz in 1973, tinkering with the transcription of a Christmas carol into his 13-Step Scale (right).
John Robinson Pierce, 1910 - 2002
(Picture courtesy of CCRMA, Stanford, CA)
Heinz Bohlen at Stanford, 2001
(Picture by Elaine Walker)
The two inventors of the Bohlen-Pierce Scale
Heinz Bohlen once commented to me that they look very similar.
The story of the Bohlen-Pierce Scale and it’s inventors is a bittersweet one. Sadly, the two microwave engineers who invented the Scale independently six years apart, never met even though they both lived in the San Francisco area for a number of years. When John Pierce passed away in 2002, Heinz's dream of meeting him and discussing their co-invented scale in person, died with him. Heinz was also a fan of John Pierce because of his fame in the microwave engineering world. John Pierce is credited for inventing the idea of the communication satellite. In turn, John Pierce may have been envious that Heinz Bohlen invented the BP Scale six years before he did.
It all started in the early 1970s when Heinz Bohlen became curious as to why musicians always use the same 12 note per octave tuning. After getting some unsatisfactory answers from musicians, he took it upon himself to research music and tonality. It was finally the understanding of combination tones that lead him to believe he could use the same method that lead to the 12 tone equal temperament, to devise another tuning from a different framework. He understood that the 12 tone scale was based around the a major triad, the inversion, and then filling in the gaps. So, he started with a new triad that was very harmonically pure, but not contained within the normal 12 tone framework. He made the stunning discovery that a scale of thirteen almost equal steps within the framework of an octave and a fifth (which John Pierce later dubbed as a tritave) contained this very pure triad. He recognized that this tuning shared a duality with the traditional Western 12 tone tuning, it had harmonic value, and that it would be a valid compositional tool.
Amazingly, during the same time frame, another man named Kees van Prooijen had independently invented the BP Scale during his research in generic equal temperaments. But even more amazingly, a second microwave engineer named John R. Pierce made the same discovery, six years later. He arrived at the tuning using a different method, but for the same reason - Curiosity. Leave it to microwave engineers to invent a tuning with no octaves! When John Pierce realized it had already been invented by Heinz Bohlen, the tuning was dubbed the “Bohlen-Pierce Scale. He was apparently unaware of Kees van Proojijen. Coincidentally, John Pierce wrote “The Science of Musical Sound”, which was my favorite childhood coffee table book. When my professor at Berklee College of Music, Dr. Boulanger, introduced me to the BP Scale in 1991, I knew the name John R. Pierce sounded familiar. That XMas I found the book in my parents living room and remembered how I loved the book when I was younger.
I had the pleasure of meeting Heinz Bohlen in 2001 in San Jose where he lived when I was on a trip to visit Stanford. We both ventured to Stanford looking for Max Mathews (the “Father of computer music”), but he was not there that week. We had hopes of having a grand reunion of Max Mathews, John Pierce, Heinz Bohlen, and myself. Dr. Richard Boulanger has also worked extensively with Max Mathews and John Pierce on Bohlen-Pierce Scale music and research. He informed me that John Pierce was in the hospital with Alzheimer's and was not taking visitors. Alas, the reunion never happened, but I found Heinz Bohlen to be delightful company over sushi. He took a great interest in my Chaos Melody Theory research and we talked about chaos theory more than the BP Scale! Heinz and I have kept in touch and remained friends ever since. - EW
 
 
I proposed this “traditional” keyboard layout as part of my thesis. It references the Lambda mode. Heinz told me he agreed that it was a good layout.
In 2007 I learned of a new controller called the AXIS by c-thru music. I created this hexagonal keyboard layout for the Bohlen-Pierce Scale on paper, and will be trying it out on the AXIS. See the links above for new layouts I have actually tried on the AXIS by just rearranging the key colors, and my proposed “Circular AXIS”. I made a series of YouTube videos as well.
A keyboard like this can be useful for a number of reasons. Due to the nature of the BP Scale, it is often necessary to make giant leaps across the keyboard or use chords with a very wide stretch. This layout makes it easier to access far-stretching keys with one hand. A large interval going to a small interval is often just a matter of rotating your hand position. Pretty neat!
For reference, the note names shown here refer to a 12 tone keyboard which has been macrotuned to the BP Scale. To play a “Phase I” triad (the most harmonically pure triad in the Bohlen-Pierce Scale) press the three circled red notes that are linked together. The 3 orange circles refer to the Phase II triad, and the yellow circles to the Phase III triad. Click here for an explanation of “Phase I, II and III triads. The notes circled in green reference the “tritaves” (as opposed to “octaves” - there are no octaves in the BP Scale) in one particular key.
Heinz and Elaine at Stanford, 2001
Bohlen-Pierce Scale Research
-Elaine Walker